Sorry if this is not a suitable topic for this group. Please advise of an more suitable group if one exists.

BACKGROUND:
I need to apply cross-hairs to the view finder window of a digital camera remote capture program for a specialized surveying application. Specifically, this is for the Canon ZoomBrowser Ex 5.0 remote capture feature. This program allows me to obtain photographs remotely while monitoring on my laptop what would be displayed on the camera's LCD screen. I have modest experience using Windows API functions. I have had some success using FindWindowEx, GetDC, ReleaseDC, SetPixel etc.

PROBLEM:
If I apply the cross-hairs to the view finder window they are immediately deleted because this window is constantly updated. I was able to apply usable red notches at the periphery of the view finder window to its parent window. However, once a photo is taken an overlapping progress bar is displayed that shows the offloading of the photo to my laptop. When it completes there is a repaint which deletes my red notches.

QUESTION:
Does anyone have any suggestions? I am thinking of perhaps using CreateDC or CreateCompatibleDC to create my own overlapping DC to the view finder window. Maybe it won't get cleared? I have no experience with these functions, experimenting will take some time and I am running out of time. I am also not optimistic.

Best regards,

Greg Wilson